One vertex per element, one color per generator, with an edge from x to x·s.
(2,5)(6,8)(9,10,13,11)(12,15,16,14)(17,18,23,24)(19,20,21,22)(25,26,30,31)(27,32,34,28)(29,33,37,39)(35,40,38,36)(9,10,13,11)(12,15,16,14)(17,19,23,21)(18,20,24,22)(26,31)(27,34)(29,37)(36,40)(10,11)(14,15)(17,20,23,22)(18,19,24,21)(25,27)(26,32)(28,31)(29,38)(30,34)(33,36)(35,37)(39,40)(1,2)(3,6)(4,5)(7,8)(9,11,13,10)(12,15,16,14)(17,21,23,19)(18,20,24,22)(25,28,30,32)(26,27,31,34)(29,36,37,40)(33,35,39,38)(1,3,4,7)(2,6,5,8)(9,12,13,16)(10,14,11,15)(17,22,23,20)(18,19,24,21)(25,29,30,37)(26,33,31,39)(27,35,34,38)(28,36,32,40)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.